The traditional process of refining magnesium adopts the Pidgeon method. The method uses a horizontal furnace. The furnace body is laid on the base with a refractory brick. A plurality of reduction tanks are laid and distributed in the furnace. The reduction tank is filled with reactant pellets. Coal or oil is taken as fuel. A manual feeding and unloading method is adopted for combustion and heating. Firstly, the reduction tank is heated with radiant heat of a reverberatory furnace outside of the reduction tank; secondly, the heat is radiated and transmitted to the reactant pellets by the reduction tank; finally, the heat is transmitted by the reactant pellets through a mutual relay method. It is a peripheral heating.
It has been proved that: as to the combustion and heating method that the refractory brick is laid and forms a big hearth, as there are a big space in the hearth, big transmitting radius of heat radiation and a blind angle of high-temperature convection flue gas, there is bad temperature uniformity, and the reduction tank is easy to be overheated, generates thermal creep, is deformed and is scrapped. Furthermore, the feeds shall be manually loaded and unloaded during each reduction cycle, and the feeding and unloading feeds may not be mechanized and automated. Therefore, the old-fashioned furnace laid with the refractory brick has the disadvantages of high labor intensity, high energy consumption, low productivity, low reduction rate, and short service life of the reduction tank. The furnace body is laid with the refractory brick. It is generally maintained every about three months and carried out with big maintenance and replacement every about one year. Therefore, the service life of the furnace body is short.